Abstract: A tool is provided for use in repairing a silcock which has a valve stem, a washer and a valve seat axially aligned with the silcock neck with the forward face of the washer being selectively rotatably driven by the stem into and out of sealing abutment with the collar of the valve seat. The tool includes a rod with a bit end and a working end. The bit end is adapted for coupling with a drilling implement for selectively rotating the rod about its longitudinal axis. The working end has a coaxial bore. A shaft has an attachment end which is snugly insertable into the bore. Preferably, the bore and the attachment end have complimentary threads to secure the shaft to the rod. Thus this shaft will rotate coaxially with the rod. A grinding head is fixed to the free end of said shaft to rotate with it. The grinding head is shaped to slide with the shaft and the rod into the silcock neck.